EEF2 and neoplasm: eEF2K can phosphorylate its only intracellular substrate protein eEF2 and inhibit the peptide-chain extension stage during protein synthesis, and reduce the consumption of amino acids and energy so that the cell can survive under metabolic stress.41,42 The expression and activity of eEF2K in some tumor cells can affect the proliferation, migration, invasion, and other physiological processes43–46 But eEF2K shows different effects in different tumor cells.